Support arm



FIG. 1 is a rear perspective view of the design;

FIG. 2 is a front perspective view of FIG. 1;

FIG. 3 is a rear elevational view of FIG. 1;

FIG. 4 is a front elevational view of FIG. 1;

FIG. 5 is a left-side elevational view of FIG. 1;

FIG. 6 is a right-side elevational view of FIG. 1;

FIG. 7 is a top plan view of FIG. 1; and,

FIG. 8 is a bottom plan view of FIG. 1.

The broken lines immediately adjacent the claim represent the bounds of the claimed design while all other broken lines are directed to environment and are for illustrative purposes only; the broken lines form no part of the claimed design. 

CLAIM The ornamental design for a support arm, as shown and described. 